Demand for roof racks has steadily increased in the late 1990's and 2000's with the increased interested in activities like kayaking, mountain biking, camping and snowboarding, to name a few. Most of these systems consist of a set of towers or feet that sit directly on the vehicle roof and attach to the bare roof, the rain gutter, or to factory-built mounting points. In vehicles that have factory-mounted roof rails running along left and right edges of the vehicle roof, a set of clamping brackets may be used. For vehicles without any factory-built mounting points or factory-mounted roof rails, universal rack kits exist that attach to the inside of a vehicle's door-jambs. In all these systems, a set of cross bars are attached to these base towers and/or clamping brackets that provide the scaffold upon which to attach activity-specific accessory racks (ski, surfboard, snowboard, bicycle, kayak, etc.) or even cargo carriers.
Companies like Yakima Products Inc. of Lake Oswego, Oreg. and Thule Group of Malmö, Sweden dominate the accessory rack market although other smaller players also make roof rack systems. Yakima and Thule make universal base kits, vehicle specific base kits, and activity specific accessory racks to fit nearly every make of car. Even OEM car manufacturers who sell their own branded base roof rack and activity specific accessory systems often contract with one of these two companies to manufacture their respective roof rack and accessory rack systems.
As a result, base roof racks can be found for nearly every non-convertible passenger vehicle found on the market. Even though racks that attach to a vehicle doorjamb are essentially universal, they are the least integrated from a design perspective and may scratch paint, damage doors seals and affect the fitment of the door into the jamb. Because of this, many automakers choose to offer factory installed roof rails or integrated mounting bases that are concealed in the roof's rain channel behind small removable plastic doors that have been painted to match the body color of the vehicle.
For metal roof vehicles this solution is acceptable because it is relatively easy to stamp metal pieces to remove the material necessary to accommodate these parts. However, recently, glass roof vehicles have been introduced such as the four door Model 3 sedan available from Palo Alto, Calif.-based Tesla, Inc., which includes a two-piece all glass roof spanning from the windshield to the trunk. Vehicles like this have very tight lines and very small gaps (less than 10 mm) between the edge of the roof glass and the metal roof supports running lengthwise along the top of the car. Removing portions of the roof glass to accommodate accessory rack mounting hardware would require cutting glass and therefore would complicate the manufacturing process and may even compromise the strength of the roof and contribute to an unattractive design aesthetic.
Consequently, there exists a need for a roof rack attachment system for use in glass roof vehicles that: 1) doesn't require modifications to the glass geometry; 2) doesn't require the addition of disposable components like plastic doors; 3) can accommodate the relatively small part gaps available in such vehicles; and 4) that contributes to a clean and integrated overall design aesthetic.